1. Field of the Invention
This invention relates to an air suspension, and more particularly to a suspension having an air spring added to a shock absorber.
2. Description of the Prior Art
A strut type air suspension comprises a shock absorber and an air spring. The air spring is constituted such that a housing is mounted on a piston rod of the shock absorber while a diaphragm is spanned between the housing and a cylinder of the shock absorber to fill an air chamber surrounded by the housing and diaphragm with compressed air. In this air spring can be adjusted a vehicle height by changing the volume of the air chamber.
Thus, in the prior air suspension, when the vehicle height is determined to a predetermined one, a spring constant could not be adjusted by changing the volume of the air chamber since the volume of the air chamber becomes constant.
Next, while not related directly to the adjustment of the spring constant, when the diaphragm is broken, air in the air chamber is exhausted so that the vehicle height may be abruptly reduced to damage the controllability.